Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Angiogenesis provides blood supply for tumor expansion and also increases the opportunity for tumor cells to enter the blood or lymph circulation. Several proangiogenic factors as well as the contribution of the microenvironment to tumor-induced angiogenesis have been identified. Among these, vascular endothelial growth factor (VEGF) and the angiopoietin (Ang) family play a predominant role involved in the growth for endothelial cells. Tumor vessels are structurally and functionally abnormal because of an imbalance of these angiogenic regulators. In contrast to normal vessels, tumor vasculature is highly disorganized, tortuous and dilated, with uneven diameter and excessive branching. In other words, the morphologic features are likely to carry additional clues that, when used in conjunction with more established parameters, can improve the present diagnostic approaches. In our study, we present a new method that helps to capture the morphologic features from three-dimensional (3-D) power Doppler ultrasound (PDUS) images. After narrowing down the vessels into their skeletons using a 3-D thinning algorithm, we extracted seven features including vessel-to-volume ratio, number of vascular trees, number of bifurcation, mean of radius and three tortuosity measures, from the skeleton and applied a neural network to classify the tumors by using these features. In investigations into 221 solid breast tumors, including 110 benign and 111 malignant cases, the p values using the Student's t-test for all features were less than 0.05, indicating that the proposed features were deemed statistically significant. The A(Z) values for these seven features were 0.84, 0.87, 0.84, 0.75, 0.77, 0.79 and 0.69, respectively. The accuracy, sensitivity, specificity, and positive and negative predictive values were 80.09% (177 of 221), 80.18% (89 of 111), 80% (88 of 110), 80.18% (89 of 111) and 80% (88 of 110), respectively, with an A(Z) value of 0.89. The preliminary results show that the proposed method is feasible and has a good agreement with the diagnosis of the pathologists.
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PMID:Computer algorithm for analysing breast tumor angiogenesis using 3-D power Doppler ultrasound. 1704 70

To investigate further the antiangiogenic potential of sunitinib for renal cell carcinoma (RCC) treatment, its effects on tumor vasculature were monitored by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using an orthotopic KCI-18 model of human RCC xenografts in nude mice. Tumor-bearing mice were treated with various doses of sunitinib, and vascular changes were assessed by DCE-MRI and histologic studies. Sunitinib induced dose-dependent vascular changes, which were observed both in kidney tumors and in normal kidneys by DCE-MRI. A dosage of 10 mg/kg per day caused mild changes in Gd uptake and clearance kinetics in kidney tumors. A dosage of 40 mg/kg per day induced increased vascular tumor permeability with Gd retention, probably resulting from the destruction of tumor vasculature, and also caused vascular alterations of normal vessels. However, sunitinib at 20 mg/kg per day caused increased tumor perfusion and decreased vascular permeability associated with thinning and regularization of tumor vessels while mildly affecting normal vessels as confirmed by histologic diagnosis. Alterations in tumor vasculature resulted in a significant inhibition of KCI-18 RCC tumor growth at sunitinib dosages of 20 and 40 mg/kg per day. Sunitinib also exerted a direct cytotoxic effect in KCI-18 cells in vitro. KCI-18 cells and tumors expressed vascular endothelial growth factor receptor 2 and platelet-derived growth factor receptor beta molecular targets of sunitinib that were modulated by the drug treatment. These data suggest that a sunitinib dosage of 20 mg/kg per day, which inhibits RCC tumor growth and regularizes tumor vessels with milder effects on normal vessels, could be used to improve blood flow for combination with chemotherapy. These studies emphasize the clinical potential of DCE-MRI in selecting the dose and schedule of antiangiogenic compounds.
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PMID:Dynamic contrast-enhanced magnetic resonance imaging of vascular changes induced by sunitinib in papillary renal cell carcinoma xenograft tumors. 1972 85